Class: Life Science Unit: Environment- Pond Water Testing Project Topic: Intro to Macroinvertebrates: Importance of macroinvertebrates & using dichotomous keys
Instructional Activities: Students should be able to:
1. Define what macroinvertebrates are 2. Use a dichotomous key to identify macroinvertebrates 3. Describe the environmental value of specific macroinvertebrates
Time & Activity
9:15-9:25A.M. Introduce and define macroinvertebrates
Distribute a Caddis Fly fact sheet to each student and discuss basic macroinvertebrate structure and life stages. Discuss basic facts about macroinvertebrates, giving definitions, examples; discuss different roles such as shredders, decomposers, etc.
9:25-9:40 Discussion of the importance of macroinvertebrates:
Stream-bottom macroinvertebrates are an important part of the community of life found in and around a stream.
Stream-bottom macroinvertebrates are a link in the aquatic food chain. In most streams, the energy stored by plants is available to animal life either in the form of leaves that fall in the water or in the form of algae that grows on the stream bottom. The algae and leaves are eaten by macroinvertebrates. The macroinvertebrates are a source of energy for larger animals such as fish, which in turn, are a source of energy for birds, raccoons, water snakes, and even fishermen.
Stream-bottom macroinvertebrates differ in their sensitivity to water pollution. Some stream-bottom macroinvertebrates cannot survive in polluted water. Others can survive or even thrive in polluted water. In a healthy stream, the stream-bottom community will include a variety of pollution-sensitive macroinvertebrates. In an unhealthy stream, there may be only a few types of nonsensitve macroinvertebrates present.
Stream-bottom macroinvertebrates provide information about the quality of a stream over long periods of time.
It may be difficult to identify stream pollution with water analysis, which can only provide information for the time of sampling. Even the presence of fish may not provide information about a pollution problem because fish can move away to avoid polluted water and then return when conditions improve. However, most stream-bottom macroinvertebrates cannot move to avoid pollution. A macroinvertebrate sample may thus provide information about pollution that is not present at the time of sample collection.
Stream-bottom macroinvertebrates are relatively easy to collect.
Useful stream-bottom macroinvertebrate data are easy to collect without expensive equipment. The data obtained by macroinvertebrate sampling can serve to indicate the need for additional data collection, possibly including water analysis and fish sampling.
9:40-9:50 Introduce and practice using a dichotomous key:
Explain the importance and use of a dichotomous key, show examples of various keys to the class
Construct a dichotomous key together with the students and work through the key with the class to identify each part
9:50-10:10 Group work: identifying macroinvertebrates and their importance:
Class broken into groups of 3-4 students per group
Distribute the Macroinvertebrate Identification Key, Macroinvertebrate handout & the Animal Identification Resource
Explain to the students that they will use their keys and reference material to identify and describe the importance of each macroinvertebrate. Students should work together in their groups to complete the worksheet. Groups will be assigned specific macroinvertebrates to research and asked to present their information to the class
Assignment:
1. (Analysis) When given a sample of macroinvertebrates, be able to use a dichotomous key to identify them 2. (Analysis) Identify a few pollution tolerant and intolerant species 3. (Comprehension) Describe in a short one page essay why we can use macroinvertebrates to describe the quality of the pond water
Class: Life Science
Unit: Environment- Pond Water Testing Project
Topic: Intro to Macroinvertebrates: Importance of macroinvertebrates & using dichotomous keys
Instructional Activities: Students should be able to:
1. Define what macroinvertebrates are
2. Use a dichotomous key to identify macroinvertebrates
3. Describe the environmental value of specific macroinvertebrates
Time & Activity
9:15-9:25A.M. Introduce and define macroinvertebrates
9:25-9:40 Discussion of the importance of macroinvertebrates:
9:40-9:50 Introduce and practice using a dichotomous key:
9:50-10:10 Group work: identifying macroinvertebrates and their importance:
Assignment:
1. (Analysis) When given a sample of macroinvertebrates, be able to use a dichotomous key to identify them
2. (Analysis) Identify a few pollution tolerant and intolerant species
3. (Comprehension) Describe in a short one page essay why we can use macroinvertebrates to describe the quality of the pond water
Activity materials needed:
1. Critters Fact Sheets: Caddies Flies class set (from the PA Fish & Boat Commission: http://www.fish.state.pa.us/mpag1.htm)
2. Macroinvertebrate handout: Field Guide to Freshwater Invertebrates (from http://www.seanet.com/~leska/Online/Guide.html)
3. Aquatic Macroinvertebrate Identification Key: a dichotomous key for each group (from http://people.virginia.edu/~sos-iwla/stream-study/key/MacroKeyIntro.HTML)
4. Animal Identification Resource: http://www.epa.gov/bioindicators/
References for lesson:
1. http://sftrc.cas.psu.edu/LessonPlans/Water/Macroinvertebrates.html
2. http://www.k12science.org
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